{"cve":"CVE-2026-25537","nvd":{"published":"2026-02-04T22:15:59.807","modified":"2026-06-17T10:24:48.953","status":"Analyzed","description":"jsonwebtoken is a JWT lib in rust. Prior to version 10.3.0, there is a Type Confusion vulnerability in jsonwebtoken, specifically, in its claim validation logic. When a standard claim (such as nbf or exp) is provided with an incorrect JSON type (Like a String instead of a Number), the library’s internal parsing mechanism marks the claim as “FailedToParse”. Crucially, the validation logic treats this “FailedToParse” state identically to “NotPresent”. This means that if a check is enabled (like: validate_nbf = true), but the claim is not explicitly marked as required in required_spec_claims, the library will skip the validation check entirely for the malformed claim, treating it as if it were not there. This allows attackers to bypass critical time-based security restrictions (like “Not Before” checks) and commit potential authentication and authorization bypasses. This issue has been patched in version 10.3.0.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P","score":5.5},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-843"],"references":["https://github.com/Keats/jsonwebtoken/commit/abbc3076742c4161347bc6b8bf4aa5eb86e1dc01","https://github.com/Keats/jsonwebtoken/security/advisories/GHSA-h395-gr6q-cpjc","https://github.com/Keats/jsonwebtoken/security/advisories/GHSA-h395-gr6q-cpjc"],"products":["keats:jsonwebtoken"],"source":"nvd","synced_at":"2026-10-19T22:22:27.261130201+00:00"},"epss":{"cve":"CVE-2026-25537","score":0.00496,"percentile":0.4258,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-h395-gr6q-cpjc","url":"https://osv.dev/vulnerability/GHSA-h395-gr6q-cpjc","summary":"jsonwebtoken has Type Confusion that leads to potential authorization bypass","modified":"2026-09-10T03:50:35.169824826Z","packages":[{"ecosystem":"crates.io","name":"jsonwebtoken","purl":"pkg:cargo/jsonwebtoken","ranges":["<10.3.0"],"fixed":["10.3.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}